I just received a call from this number. Did not leave VM either

I keep getting calls from this number and there is no message left.

I answered this call and told me I won a prize or something.

I received a call from this #, caller ID said unidentified caller, so I didn't pick up.  An automated message was left, saying I had won something.  
Called the # back frequently, when an unsolicited call comes in w/ phone # listed, if one calls that # back, the vm chain has an option for removing oneself from call list, this proved to be the case, so I entered the option for "remove me from your list."

Y'all will hear back from me if they call again!

I was getting calls from two other similar numbers (from the same company) on my CELL phone, but I blocked them. Now I'm getting calls from this one. It's spam! Driving me crazy.